Method and apparatus for encoding and decoding HDR images

A method comprising:

• receiving one or more signals;
• decoding second images depicting a lower dynamic range version of first images from the one or more received signals;
• accessing information from the one or more received signals, the accessed information including a parameter used to encode the second images;
• using the parameter as an input when generating an inverse tone mapping function;
• and
• generating the first images from the decoded second images based on the inverse tone mapping function.

A data transmission apparatus comprising:

• a tone curve estimator configured to determine a tone mapping function based on images and at least one encoding parameter;
• an image generator configured to determine a lower dynamic range version of the images from the images based on the tone mapping function;
• and
• an encoder configured to encode the lower dynamic range version of the images and information including a parameter used to encode the determined lower dynamic range version of the images, wherein the parameter is used as an input to generate an inverse tone-mapping function;
• and
• a transmitter configured to transmit the encoded lower dynamic range version of the images and information in one or more signals.

A data receiving apparatus comprising:

• a receiver configured to provide one or more signals;
• a decoder configured to decode second images depicting a lower dynamic range version of first images from the one or more received signals;
• a processor configured to:
• access information from the one or more signals, the accessed information including a parameter used to encode the second images;
• use the parameter as an input when generating an inverse tone mapping function;
• and
• an image generator configured to generate the first images from the decoded second images based on the inverse tone mapping function.

A non-transitory computer-readable storage medium having stored instructions that, when executed by a processor, cause the processor to perform:

• determining a tone mapping function based on images and at least one encoding parameter;
• determining a lower dynamic range version of the images from the images based on the tone mapping function;
• encoding the lower dynamic range version of the images and information including a parameter used to encode the determined lower dynamic range version of the images, wherein the parameter is used as an input to generate an inverse tone-mapping function;
• and
• transmitting the encoded lower dynamic range version of the images and information in one or more signals.

A non-transitory computer-readable storage medium having stored instructions that, when executed by a processor, cause the processor to perform:

• receiving one or more signals;
• decoding second images depicting a lower dynamic range version of first images from the one or more received signals;
• accessing information from the one or more received signals, the accessed information including a parameter used to encode the second images;
• using the parameter as an input when generating an inverse tone mapping function;
• and
• generating the first images from the decoded second images based on the inverse tone mapping function.